During processing of aircraft fuselage panels made of a carbon fibre reinforced plastics material, contamination by chips or abrasive agents is caused by processing steps such as grinding or milling and the water jet cutting process. Contaminants of this type penetrate in particular into hollow spaces of hollow profiles, which are formed on the aircraft fuselage panel for example by what are known as stringers. Cleaning and drying said stringers after said component blank of an aircraft fuselage panel has been mechanically processed is very time consuming and expensive. Therefore, it is desirable for the open ends of said hollow spaces to be closed and sealed before the mechanical processing step.
If this sealing takes place after the component blank is thermally treated, therefore, when said blank is removed for example from the autoclave, in the case of materials hitherto known for this purpose for closure stoppers for sealing the opens ends of the hollow profile, problems arise when the component blank is tested by means of ultrasound, which takes after the thermal processing, since the boundary between the component wall and the stopper does not make it possible for any ultrasound to be effectively reflected. The material hitherto available for stoppers of this type absorbed the ultrasound. In order for it to be possible to carry out reliable material testing of the component blanks, it was therefore previously necessary to insert the stoppers into the open ends of the hollow profile in an additional handling step after the material testing step by means of ultrasound, and this was very time-consuming.